Ahmed Yehia Gad

Citation:

Joyce, K., A. Gad, N. G. Menjivar, S. Gebremedhn, D. Heredia, G. Dubeux, M. C. Lopez-Duarte, J. Bittar, A. Gonella-Diaza, and D. Tesfaye, "Seasonal environmental fluctuations alter the transcriptome dynamics of oocytes and granulosa cells in beef cows", Journal of Ovarian Research, vol. 17, issue 1, pp. 201, 2024.

Abstract:

Examining the mechanistic cellular responses to heat stress could aid in addressing the increasing prevalence of decreased fertility due to elevated ambient temperatures. Here, we aimed to study the differential responses of oocytes and granulosa cells to thermal fluctuations due to seasonal differences. Dry beef cows (n = 10) were housed together, synchronized and subjected to a stimulation protocol to induce follicular growth before ovum pick-up (OPU). Two OPU’s were conducted (summer and winter) to collect cumulus-oocyte-complexes (COCs) and granulosa cells. In addition, rectal temperatures and circulating blood samples were collected during OPU. Oocytes were separated from the adherent cumulus cells, and granulosa cells were isolated from the collected OPU fluid. RNA was extracted from pools of oocytes and granulosa cells, followed by library preparation and RNA-sequencing. Blood samples were further processed for the isolation of plasma and leukocytes. The transcript abundance of HSP70 and HSP90 in leukocytes was evaluated using RT-qPCR, and plasma cortisol levels were evaluated by immunoassay. Environmental data were collected daily for three weeks before each OPU session. Data were analyzed using MIXED, Glimmix or GENMOD procedures of SAS, according to each variable distribution.

Notes:

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